The field of the present invention is the construction and use of power turbines, which in one example, may be used to drive an electrical generator.
Power turbines are essential to modern life. They are used to drive electrical generators, power vehicles, and drive industrial equipment. Generally, a power turbine uses an energy source to generate a mechanical kinetic power that may be used in another process. Often, the power turbine is driven by steam from a boiler, or may be driven by water, for example, at a hydroelectric facility. In converting the energy source into usable power, the power turbine also consumes some of the energy, and may allow some of the energy to be wasted in the conversion process. Accordingly, all power turbines have an energy conversion efficiency rating, which is a measure of how effectively the power turbine converts energy to usable power.
To more effectively utilize energy sources, and to reduce the size of the power turbines, it is desirable to use turbines with higher conversion ratings. Accordingly, the power turbine industry is continually advancing turbine technology to develop more efficient and better performing power turbines. One such advancement was the Tesla turbine. The Tesla turbine was developed in the early 1900's, and was touted as having very high efficiency ratings, possibly even well over 90%. The Tesla design is well known, but generally uses a set of closely aligned disks in a housing. Steam is injected at the circumference of the disks, which spirals to the center, where the steam is ejected. The spiraling seam uses a molecular adhesion process to transfer energy to the disks, which drive a central shaft. In order to achieve good efficiencies, the spiraling path has to made as long as possible, which requires that the Tesla turbine spin very fast, for example, at 30,000 to 40,000 rpm. This also meant that if the turbine slowed when under load, the turbine would quickly and dramatically lose power, leading to catastrophic failure of the drive process. Further, the fast rotational speed also meant that complex and sophisticated transmission systems had to be employed to bring the speed down to a more usable rate.
With these practical limitation to the Tesla turbine, it has failed to achieve widespread adoption. Instead, the Tesla technology is primary used as a pump. As a pump, liquid is pulled into the center of the disks, and the rotating disks use a centrifugal force to drive the liquid to the outer circumference, where the liquid is extracted. The Tesla pump is widely used, and is recognized as being capable of reliably pumping many types of liquids.
Accordingly, there exists a need for a power turbine with better efficiency.